The human mind tends to suffer from a number of well documented cognitive biases that distort our ability to predict accurately.
For example, we give too much weight to unusual events and once we form a mistaken belief about something, we tend to cling to it!

Are we good at making predictions?

For each of the ten following questions, give the range of answers that you are 90 percent confident contains the correct answer. For example, for the first question, you are supposed to fill in the blanks : “I am 90 percent confident that Martin Luther King’s age at the time of his death was somewhere between ___ years and ___ years.”

Don’t worry about not knowing the exact answer and refrain from using Google.

Answering “I have no idea” is not allowed since of course, you have some idea: you know that the deepest point in the ocean is more than 2 inches and less than 100,000 miles.

So, let's begin:

1. What was Martin Luther King, Jr’s age at death?
2. What is the length of the Nile River, in miles?
3. How many countries belong to OPEC?
4. How many books are there in the Old Testament?
5. What is the diameter of the moon, in miles?
6. What is the weight of an empty Boeing 747, in pounds?
7. In what year was Mozart born?
8. What is the gestation period of an Asian elephant, in days?
9. What is the air distance from London to Tokyo, in miles?
10. What is the deepest known point in the ocean, in feet?

Conclusion...

If all ten of your intervals include the correct answer, you are either under confident or one the best among us.

But it seems that almost everyone who answers those questions has the opposite problem of overconfidence – we cannot help ourselves from reporting ranges that are too small!

In fact, when researchers tested more than 1,000 people, they found that most people missed between four and seven of the questions. Less than 1 percent of the people gave ranges that included the right answer nine or ten times. Ninety nine percent of people were overconfident!